<template>
  <section class="msite">
    <!--首页头部-->
    <HeaderTop :title="address.name">
      <span class="header_search" slot="left">
            <i class="iconfont icon-sousuo"></i>
      </span>
      <span class="header_login" slot="right">
            <span class="header_login_text">登录|注册</span>
      </span>
    </HeaderTop>
    <!--首页导航-->
    <nav class="msite_nav">
      <div class="swiper-container" v-if="categorys.length>0">
        <div class="swiper-wrapper">
          <div class="swiper-slide" v-for="(categorys,index) in categoryArr" :key="index">
            <a href="javascript:" class="link_to_food" v-for="(category,index) in categorys" :key="index">
              <div class="food_container">
                <img :src="baseImageUrl+category.image_url">
              </div>
              <span>{{category.title}}</span>
            </a>
          </div>

        </div>
        <!-- Add Pagination -->
        <div class="swiper-pagination"></div>
      </div>
      <img src="./images/msite_back.svg" alt="back" v-else>
    </nav>
    <!--首页附近商家-->
    <div class="msite_shop_list">
      <div class="shop_header">
        <i class="iconfont icon-xuanxiang"></i>
        <span class="shop_header_title">附近商家</span>
      </div>
      <ShopList></ShopList>
    </div>
  </section>
</template>

<script>
  //一如swiper和swiper.min.css
  import Swiper from 'swiper'
  import 'swiper/css/swiper.min.css'
  import{mapState} from 'vuex'
  import HeaderTop from '../../components/HeaderTop/HeaderTop.vue'
  import ShopList from '../../components/ShopList/ShopList.vue'
  export default {
    data(){
      return{
        baseImageUrl: 'https://fuss10.elemecdn.com'
      }
    },
    mounted(){
      //读取数据
      this.$store.dispatch('getCategorys')
      this.$store.dispatch('getShops')
    },
    watch:{
      categorys (value) { // categorys数组中有数据了, 然后异步更新界面之前执行
        //界面更新就立即创建Swiper对象
        this.$nextTick(()=>{//一旦界面完成更新，立即调用（写在数据更新之后）
          //创建一个Swiper实例对象，来实现轮播
          new Swiper('.swiper-container',{
            loop:true,//可以循环轮播
            // 如果需要分页器
            pagination: {
              el: '.swiper-pagination',
            }
          })
        })
      }
    },
    computed:{
      ...mapState(['address','categorys']),
      /*根据categorys一维数组生成一个二维数组*/
      categoryArr(){
        const {categorys} = this
        //准备空的二维数组
        const arr = []
        let minArr =[]
        //遍历categorys
        categorys.forEach(c=>{
          //如果当前小数组满了，创建一个新的小数组
          if(minArr.length===8){
            minArr=[]
          }
          //如果minArr是空的，将小数组保存到大数组中
          if(minArr.length===0){
            arr.push(minArr)
          }
          minArr.push(c)
        })
        return arr
      }
    },
    components:{
      HeaderTop,
      ShopList
    }

  }
</script>

<style lang="stylus" rel="stylesheet/stylus">
 @import "../../common/stylus/mixins.styl"
  .msite  //首页
    width 100%
    .msite_nav
      bottom-border-1px(#e4e4e4)
      margin-top 45px
      height 200px
      background #fff
      .swiper-container
        width 100%
        height 100%
        .swiper-wrapper
          width 100%
          height 100%
          .swiper-slide
            display flex
            justify-content center /*	swiper-slide下面的a标签项目位于容器的中心*/
            align-items flex-start/*	swiper-slide下面的a标签项目位于开头*/
            flex-wrap wrap  /*让弹性盒元素(swiper-slide下面的a标签)在必要的时候拆行：*/
            .link_to_food
              width 25%
              .food_container
                display block /*默认排列方式为从上至下*/
                width 100%
                text-align center
                padding-bottom 10px
                font-size 0
                img
                  display inline-block/*行内块元素默认排列方式为从左到右*/
                  width 50px
                  height 50px
              span
                display block
                width 100%
                text-align center
                font-size 13px
                color #666
        .swiper-pagination
          >span.swiper-pagination-bullet-active
            background #02a774
    .msite_shop_list
      top-border-1px(#e4e4e4)
      margin-top 10px
      background #fff
      .shop_header
        padding 10px 10px 0
        .icon-xuanxiang
          margin-left 5px
          color #999
        .shop_header_title
          color #999
          font-size 14px
          line-height 20px /*行高*/
</style>
